Heating apparatus



Sept. 25, 1945. w.` v. RIFLE HEATING APPARATUS Filed March 25, 1942 Patented Sept. 25, 1945 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to improvements in heating apparatus.

a transverse partition I6 within a suitable outer casing I'I. Preferably surrounding the radiator I5 In the use of gas as a fuel in heating homes or v other buildings where the heating apparatus eX- hausts the products of combustion into chimneys, diiiiculties have been encountered by reason of hausts the products of combustion into chimneys, during cold weather. In cold weather the condensate sometimes is suiiicient in quantity to follow down the exhaust flue and drip upon the floor within the building or run down the wall beneath the chimney opening. In severe winter Weather, there have been instances where the draft through a chimney has been impaired r practically eliminated by the freezing of the condensate within the chimney, thus causing back pressure within the furnace exhaust ue which has resulted in improper induction of suicient secondary air for proper combustion purposes and has thereby cre ated a condition hazardous to health as Well as a reduction in the heating efliciency of the furnace.

It is an object of the present invention to provide improved heating apparatus which eliminates the formation of troublesome or dangerous condensate in chimneys and which by providing for an augmented flow of products of combustion through the exhaust flue and chimney assures an adequate supply of secondary airfor the burner for maintaining the same at desired operating eiciency. l

Another object of the invention is to provide means for preventing the formation of condensate within the chimney in objectional quantities and thereby avoid the inconveniences and dangers above referred to.

Other objects and advantages of the invention will be apparent from a consideration of the following speciiication and accompanying drawing wherein,

Figure l is an elevation (partly in section) of heating apparatus illustrating the present improvements;

Fig. 2 is an enlarged broken View of a main hot air duct and a control therein; and

Fig. 3 is an end elevation of the structure shown in Fig. 3.

In the drawing, I0 generally indicates a furnace designed to utilize gas, either natural, artificial or a mixture thereof, as fuel. The burner II comprises, in the form illustrated a plurality of gas tubes I2, the fiames which form at the upper ends thereof when the gas is ignited extending into a cylindrical inlet I3 which projects downwardly from a conical base I4 of a heating drum-.or radiator I5. The radiator I5 .is shownsupported .on

within the casing I1 is a casing I8, spaced from both the radiator I5 and the outer casing and also secured to the partition IG. The radiator I5 as well as the casing I8 are closed at their upper ends and make air tight Contact with the supporting partition or base I6 for preventing pollution of fresh heated air with products of combustion from the burner.

The products of combustion rise from the burner into the radiator I5 and exhaust therefrom through a fiue I9 extending into a chimney 20, in the embodiment of the invention illustrated, and upwardly therethrough for conveying the combustion products to the exterior of the building. The casing I8, which, as stated, surrounds the radiator receives air to be heated from a motor blower unit 2|, the discharge nozzle 22 of which directs the air against the conical bottom I4 of the radiator and thence into a hot air manifold or distributing duct 24 which surrounds the exhaust flue I9. From the manifold 24 the ho-t air is distributed to the rooms to be heated by hot air ducts 25 two only being shown for the purpose of illustration.

A cold air return duct 26 delivers air from one or more places in the room or rooms to be heated to a casing 21 which communicates with the intake of the blower unit 2| whereby effective circulation of the air is provided. In the casing 2'! is located a suitable air filter indicated by the numeral 28 for filtering dust and foreign particles from the air circulation system.

The air distributor duct or manifold 24, instead of extending merely beyond the air duct 25 most remote from the furnace IU, also extends into the chimney and upwardly to the upper end thereof where it is closed by a chimney cap 29. Throughout the length of the duct 25, therefore, it encloses the flue I 9 and hence the air flowing within the duct 24 is in heat transfer relation with respect to the iiue. The flue therefore constitutes in effect an extension of the heat radiating surface of the radiator I5 and the latter may be somewhat less in radiating surface than would otherwise be required and the size of the furnace therefore of smaller ldimensions than would be the case were the radiator I5 of the size required to heat the air to the maximum degree. In fact the temperature of the heated air as it enters the duct 24 from the radiator chamber 23 may be and preferably is lower or at least not higher than the temperature of theair that enters the distributor duct 25 most remote from the furnace. The air in flowing along the duct t24 to the remote duct 25 continues to absorb heat from the flueV I9 and hence the room orarea served by that remote duct 25 receives a proper portion of heat from the furnace notwithstanding that the velocity of hot air through that remote duct may be lower than through the other` ducts 25 which are less remote from the blower. Hence, to compensate for the reduced velocity of air delivered to the different floor or wall registers 3|), land the Y heat losses of theY duct 24, the arrangement pref-'- erablyY is suchthat the air flowing along the duct 24 increases in temperature at least to that pore tion thereof with which the remote duct 25 communicates. f

vThe air space within the duct 24 beyond the re-` mote air distributor 25 constitutes an insulation shell for the flue I9 substantially or entirely throughout the portion of the latter that is eX` posed to temperatures within the chimney and hence condensation of moisture or of other gasesv within the ue is prevented or substantially pre-- jvented. The vertical portion 24a of the duct 24 whichY is disposed within the chimney 20 preferably is spaced from the chimney walls and encloses the stack ISa and since the upper end ofV the chimney, as well as the upper end of the duct 24a are closed by the cap 29, the influence of exterior temperatures on the rising gases in the nue is at a'minimum. By reason of this ar rangement it is not necessary to maintain or attemptY to maintain a relatively high stack ternperature for the purpose of preventing or reducing condensation'in cold weather as generally has been required heretofore. In fact, due to the insulation of the stack or lvertical portion i9a of the flue by the surrounding jacket or duct 24a, condensation is avoided within kthe flue even undersevere weather conditions since the space between the duct 24a and the stack- I9a, while generally in a comparatively static condition, is

. .orl may be placed in direct communication with the hotV air in the horizontal portion of the duct 24.V Air circulation takes place within the air space of the vertical duct portion 24a, the hot air therein'tending to rise to the top, thus preventing condensation near the cooler outlet end of the stack.. By reason of the insulation of the stack( as mentioned and the inhibition of condensation 4 within the flueV produced thereby, a lower temperature of the flue gases is feasible without likeflihood that condensation will occur even during severe winter weather. For the purpose of further guarding against condensation in the stack and improving the operation of the furnace, the flue "preferably is provided with a port 39 having a hood 3l adjacent the same and provided withV aninlet at the forward or right hand side thereof as viewed in Fig. 1. Depending within the hood opening is a light weight pivotedY check valve 32 which normally admits Yinto the flue a small ue through the port 30 preferably can be controlled by a suitable damper indicated generally by the numeral 34 positioned to the right of the port. The damper, in the form illustrated, Comprises a stationaryV ring 35, having a central opening through which the flue I9 passes. A plurality of ports 36 are provided in the web of the member 35 which may be closed wholly or partially e partially withV the openings 35. `The damper may by the adjustable valve or damper 31 arranged for arcuate adjustment with respect to the member 35 by means of a handle 38 which projects'Y be adjusted to the position wherein the openings thereof are out of registration with the openings 36 for preventing the passage of air from the duct beyond the damper. Hence during mild weather the handle 38 can be adjusted to reduce thequantity of air delivered to the flue. A second damper 40 similar to damper 34 is shown onV the opposite side of the port 30, that is, between the port and the chimney, which may be employed when desired. By adjusting the damper, flow of air into the vertical portion of the duct 24 caribe controlled. Hence in fall or spring or during mild winter weather no hot air may be required within the vertical section 24a of the duct 24 to pre'- vent condensation or excessive cooling of the Y combustion gases within the flue and hence the damper 40 may be wholly or partially closed while in severe weather it maybe opened.

When damperv is closed and damper 34 is wholly or partially opened, air will be directed intoV the flue in controlled amount for augmenting the nowof the products through the liue and assure ran adequate flow of'secondary air to the burner.

the duct 24 is prevented by the light weight valvek stream of air from the duct 24, the air being Y directed. into tno nue in tno direction of 'the now ,of gases within the iiue.

The valve 32 tends Vto swing normally to closed position but is swung to openV position by the pressure ofthe air maintained within the duct 2,4 by the blower 2i. The air admittedinto the duct being hotl and'of relatively low humidity as compared with, the nue Ygases reduces the relative humidity thereof Yand Yhence assists in maintaining theinterior of the stack in a dry condition. The impulse given to kthe flue 'gases by the air injected into the same V tends to Vaugment the flow of thek samevertically through the stack.

32 which acts'as a check valve which is closed whenever pressure in the ue is in excess of the f pressure within the duct 24. rlhe ue I9 and manifold duct 24'are shown in horizontal position but such arrangement is not essential. It will be seen, howeventhat the injection of the air through the port 3i! into the flue I9 augments the flow of gases toward and throughY Vthe stack I9a and henceV provides, in effect a forced draft ofV secondary air to the burner H and tends to prevent back pressure of gases within the nue I9 and stackid and improper combustion at the burner.

It will be understood that various automatic safety devices are employed, such asia gas con-,- trol for shutting off the entire ow of gas to the burner should the motor of the blowerstop'for any reason, a pilot,V a pilot control and other de- I sired.

i whiietne vertical portion zdof'offihe duct. 24V is showniwithin a chimney 2|), it will be apparent that the arrangement of the capped duct 24 in insulating relationship with respect to the Vent pipe or stack |9a may be employed where no chimney is available if desired. Other modications of the illustrated embodiment of the invention may be resorted to without departing from the spirit of the invention.

I claim:

l. Heating apparatus comprising a burner, a radiator into which the products of combustion pass from the burner, a flue extending from the radiator to a place of discharge, a casing enclosing said radiator, a duct extending from the casing and enclosing said flue substantially throughout the length of the latter in spaced relation with respect thereto and provided with a closure member at the discharge end of the flue, one or more heat distributor conduits extending from said duct in spaced relation therealong, means for forcing air to be heated into said casing and along said duct and `through said conduit or conduits, and means for directing air under pressure from the duct into said iiue at a point between the conduit most remote from the casing and the closed outer end of the duct.

2. Heating apparatus comprising a burner, a radiator into which the products of combustion pass from the burner, a flue extending from the radiator to a place of discharge, a casing. enclosing said radiator, a duct extending from the casing and enclosing said flue in spaced relation with respect thereto and provided with a closure member at the end thereof remote from `the casing, one or more heat distributor conduits extending from said duct in spaced relation therealong, means for forcing air to be heated into said casing and along said ductand through said conduit or conduits, means for directing air under pressure from the duct into said ue at a point between the conduit most remote from the casing and the outer end of the duct, and adjustable means located between said means and said conduit for controlling the flow of air into the ue.

WILLIAM V. RIFLE.

CERTIFICATE 0F CORRECTION. Patent No.' 2,585,652. september 25, 1915.

wILLIAM v. RIFIE.-

` It is hereby certified that error appears in the printed specification ofthe above .numbered patent requiring correction as lfollows: Page l, first column, line 7, strike out "hausts the precincts of combustion into.Cl'lflfllfleqs' and insert `instead --the condensation that occrs in the chimneys--g andl that the said Letters Patent should be refa'd with this correction therein that the same may conform to the record of` the case in the Patent Office.

Signed and sealed this kl8th=day of vDecemoeIgH-I.. l). 19145.

Leslie Frazer (Seal) First lAssistant Comxnissiomerv oiv lPatents. 

